losing crank sync bent reluctor?
Thread Starter
Staging Lane
Joined: Jul 2014
Posts: 95
Likes: 2
From: Northern Michigan
losing crank sync bent reluctor? Hey all, just got my engine in my car a month or so back. First start up was good then it seemed once we got ready to tune the car wot was freaky acting. the car lost sync and would create what seems like a rev limiter at 2k.. Switched the crank sensor and fixed that. Then started to do wot tuning and the car has a fake rev limiter at 6500 rpms now will not get worse like it originally did, but wont get better and sometimes will carry into second gear even and act up at 4k... Dove into more of the car found the 24x wheel was a bit separated. would a separation on the wheel make this issue? I would assume it should act funky all over the place or not even start... We are going to pull the crank and get a billet wheel installed now hoping this is the issue.
car is a fox with a ls1 stroked and bored darton sleeved, ms3 evo computer and a powerglide. so you can see why the rpms are needed. if it was a turbo400 and didnt carry over the problem after a shift i wouldn't be as pressed to fix it but i cant even make a quarter mile pass and i still shift before the eightht so i cant even do short track fun... anyone use ms3 and have a similar problem or have a bent wheel and have similar problems?
car is a fox with a ls1 stroked and bored darton sleeved, ms3 evo computer and a powerglide. so you can see why the rpms are needed. if it was a turbo400 and didnt carry over the problem after a shift i wouldn't be as pressed to fix it but i cant even make a quarter mile pass and i still shift before the eightht so i cant even do short track fun... anyone use ms3 and have a similar problem or have a bent wheel and have similar problems?
Thread Starter
Staging Lane
Joined: Jul 2014
Posts: 95
Likes: 2
From: Northern Michigan
We did not measure it was in the car and we just used a scope to look at it will turning the engine by hand. It is noticeable by the naked eye. I just figured if it was causing issues at 6000+ rpms it would cause problems ever place else. I forgot to mention i was using a parts store sensor at first then swapped to a factory sensor to get the results i am currently having.. I'm sure it has something to do with the issue but was just puzzled why the car works everywhere else in the rpm band..
OP if it’s super noticeable by the eye then you have more run out than spec. Could that be the source of your issue? Maybe or maybe not, but I would bet that is the primary source of it.
Thread Starter
Staging Lane
Joined: Jul 2014
Posts: 95
Likes: 2
From: Northern Michigan
Was leaning towards it being the problem as I said I'm doing a billet wheel tomorrow. Just makes me wonder why it isn't affecting anywhere else the car performs besides when it shifts out of it into second gear it occasionally does act up. I figured it would be funny at lower rpms but it drives perfectly normal below 6k even when babbying into the trouble spot it acts up. I'm the kind of guy where it'll get fixed but I'll still wonder what the heck. Bwe back with updates by Saturday.
Its tighter than that. Reluctor Ring RO: 0.25mm / 0.01" (Measured @ 1.0mm/0.04" below tooth Dia.)
OP if it’s super noticeable by the eye then you have more run out than spec. Could that be the source of your issue? Maybe or maybe not, but I would bet that is the primary source of it.
OP if it’s super noticeable by the eye then you have more run out than spec. Could that be the source of your issue? Maybe or maybe not, but I would bet that is the primary source of it.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
TECH Senior Member
Joined: Jun 2016
Posts: 22,293
Likes: 3,617
From: Central Cal.
Im not doubting that if he can see it it's way out. I'm simply saying what I acceptable from a sensor and PCM perspective. I've seen them 60 thou out and knocked back to within 10 by hand using a dial indicator.
Thread Starter
Staging Lane
Joined: Jul 2014
Posts: 95
Likes: 2
From: Northern Michigan
The reason for the post wasn't asking if the run out was the problem it was why is it only an intermittent problem and not affecting the car besides at 6k rpm not even wot pulls it will even happen when i half throttle past 6k...
Well, let’s look at what you’ve figured out. The behavior changes for the better upon the replacement of the crank sensor with an OEM unit, but you still have a weird issue.
I suspect crank signaling is still your problem. Whether it be from the reluctor(which I suspect is out of tolerance) or the signal is breaking up from interference from something else electronic in the car.
Do you have an electronic scope like a PICO or similar? Also is this a you made harness or a vendor make harness for your swap? Because when you get the reluctor run out deal straightened out and on the chance still does it then you need to scope the various sensors on the motor to find out if your signal is breaking up.
I suspect crank signaling is still your problem. Whether it be from the reluctor(which I suspect is out of tolerance) or the signal is breaking up from interference from something else electronic in the car.
Do you have an electronic scope like a PICO or similar? Also is this a you made harness or a vendor make harness for your swap? Because when you get the reluctor run out deal straightened out and on the chance still does it then you need to scope the various sensors on the motor to find out if your signal is breaking up.
TECH Senior Member
Joined: Jun 2016
Posts: 22,293
Likes: 3,617
From: Central Cal.
Sounds like past 6000RPM it has a harder time reading it due to the slight reluctor alignment issue. I still think if you fix the reluctor it will go away.
Last edited by G Atsma; Jun 9, 2018 at 03:06 PM.
Thread Starter
Staging Lane
Joined: Jul 2014
Posts: 95
Likes: 2
From: Northern Michigan
Thread Starter
Staging Lane
Joined: Jul 2014
Posts: 95
Likes: 2
From: Northern Michigan
Well, let’s look at what you’ve figured out. The behavior changes for the better upon the replacement of the crank sensor with an OEM unit, but you still have a weird issue.
I suspect crank signaling is still your problem. Whether it be from the reluctor(which I suspect is out of tolerance) or the signal is breaking up from interference from something else electronic in the car.
Do you have an electronic scope like a PICO or similar? Also is this a you made harness or a vendor make harness for your swap? Because when you get the reluctor run out deal straightened out and on the chance still does it then you need to scope the various sensors on the motor to find out if your signal is breaking up.
I suspect crank signaling is still your problem. Whether it be from the reluctor(which I suspect is out of tolerance) or the signal is breaking up from interference from something else electronic in the car.
Do you have an electronic scope like a PICO or similar? Also is this a you made harness or a vendor make harness for your swap? Because when you get the reluctor run out deal straightened out and on the chance still does it then you need to scope the various sensors on the motor to find out if your signal is breaking up.
Thread Starter
Staging Lane
Joined: Jul 2014
Posts: 95
Likes: 2
From: Northern Michigan
Update: Wheel was separated worse than i though once i took the crank out. Replaced with a billet callies wheel and new crank that hasn't been cut just for piece of mind. For future builds we're always using a one piece wheel on the 24x reluctor cars. Unless the problem continues which i doubt after we start up and tune, this thread has closure for anyone else that has the same issue in the future.
Thread Starter
Staging Lane
Joined: Jul 2014
Posts: 95
Likes: 2
From: Northern Michigan
Yes the two sets were apart i have them on the old crank still can get pictures tonight if i remember. It didn't seem bad until it was next to a stock wheel that had no issue. Engine is back together just waiting to get help to lift it in.
